When a patient suffers a medical condition, such as a stroke, that affects the patient's ability to move one or more joints, the patient routinely undergoes physical rehabilitation, in an effort to recover mobility and control of the joint. In one form of conventional physical rehabilitation, a therapist pushes or slides the patient's joint through a plurality of movement phases of a movement cycle. To reduce tedium and variability of such physical therapy, exoskeletal robots have been introduced. A conventional form of such physical rehabilitation involves the use of the exoskeletal robot that is attached to the impaired joint, to impose prescribed dynamics of a healthy joint on the impaired joint, over a plurality of movement phases.